ASSESSMENT OF FIRE HAZARD UNDER EXPLOSIVE SPALLING DEVELOPMENT IN REINFORCED CONCRETE STRUCTURES

Abstract

The present study examines the fire hazard associated with the development of explosive spalling in reinforced concrete structures under fire exposure. Special attention is given to the mechanisms of concrete layer separation caused by thermal stresses and internal vapor pressure. The influence of explosive spalling on the reduction of the effective cross-section, exposure of reinforcement, and decrease in load-bearing capacity is analyzed. It is shown that the asymmetric loss of concrete cover may lead to eccentricity of the applied load and the occurrence of additional bending moments, which accelerate structural failure. The study also discusses the impact of this phenomenon on the overall fire resistance and structural reliability of buildings. Particular emphasis is placed on preventive protection measures aimed at reducing the risk of explosive spalling and improving structural fire safety.